High Confidence - Carbohydrates Flashcards
What elements make up carbohydrates?
Carbon / Hydrogen / Oxygen
What are the monomers of carbohydrates called?
Monosaccharides
Name two monosaccharides.
Glucose / Ribose
What are the two forms of glucose?
a-glucose / β-glucose
What is the difference between a hexose and pentose monosaccharide?
A hexose monosaccharide has 6 carbon atoms, a pentose monosaccharide has 5 carbon atoms.
Where would you find ribose?
It is the sugar component in RNA nucleotides.
What are the bonds that form between monosaccharides?
Glycosidic bonds
What is the main energy store in plants and why is it a good energy store?
Starch
It is insoluble in water so it does not cause water to enter cells by osmosis, which would make them swell.
Name two alpha-glucose polysaccharides.
Amylose
Amylopectin
What do animals store excess glucose as?
Glycogen
What is a major component in the cell walls of plants?
Cellulose
What role does cellulose play in plants?
Provides structural support for cells (plant cell wall).
In a test for starch, what colours indicate a positive and negative result.
Positive - Dark blue/black
Negative - Browny-orange
What test do you conduct to detect the presence of sugars?
Benedict’s test
What can all sugars be classified as?
Reducing and non-reducing sugars.
What do reducing sugars include?
All monosaccharides and some disaccharides e.g. maltose and lactose
Why should you use an excess of Benedict’s solution?
To make sure all the sugar reacts.
After a negative Benedict’s test, what should happen next?
A test for non-reducing sugars should be conducted.
What might you use to determine the concentration of sugar in a solution?
Colorimetry
What does a colorimeter do?
Measures the amount of light absorbed by a solution.
What are the axis labels for a calibration curve?
x - absorbance value
y - concentration of glucose
